ご覧いただきましてありがとうございます。
早速本題についてです。

R1(config)#no ip route 192.168.20.0 255.255.255.0 192.168.10.1
R1(config)#ip route 192.168.20.0 255.255.255.0 10.10.200.2

という選択肢が不正解選択肢として扱われておりますが、
OSPFのネイバー関係がR1、R2、R3で正しく成立しているのであれば、
10.10.200.2というという宛先アドレスは再帰的処理がされて、
PC1-PC2の間のpingを成功させることが出来ると思います。

下記に簡易的にpacket tracerで作成したR1のconfigを記載します。
R1(config)#!
R1(config)#ip route 192.168.20.0 255.255.255.0 192.168.10.1
R1(config)#!
R1(config)#do show run | in ip route
ip route 192.168.20.0 255.255.255.0 192.168.10.1
R1(config)#do show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route

Gateway of last resort is not set

 10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

C 10.10.100.0/24 is directly connected, GigabitEthernet0/0/1
L 10.10.100.1/32 is directly connected, GigabitEthernet0/0/1
O 10.10.200.0/24 [110/2] via 10.10.100.2, 00:16:12, GigabitEthernet0/0/1
192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.10.0/24 is directly connected, GigabitEthernet0/0/0
L 192.168.10.254/32 is directly connected, GigabitEthernet0/0/0
S 192.168.20.0/24 [1/0] via 192.168.10.1

R1(config)#!
R1(config)#!
R1(config)#no ip route 192.168.20.0 255.255.255.0 192.168.10.1
R1(config)#ip route 192.168.20.0 255.255.255.0 10.10.200.2
R1(config)#!
R1(config)#do show run | in ip route
ip route 192.168.20.0 255.255.255.0 10.10.200.2
R1(config)#do show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route

Gateway of last resort is not set

 10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

C 10.10.100.0/24 is directly connected, GigabitEthernet0/0/1
L 10.10.100.1/32 is directly connected, GigabitEthernet0/0/1
O 10.10.200.0/24 [110/2] via 10.10.100.2, 00:16:12, GigabitEthernet0/0/1
192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.10.0/24 is directly connected, GigabitEthernet0/0/0
L 192.168.10.254/32 is directly connected, GigabitEthernet0/0/0
S 192.168.20.0/24 [1/0] via 10.10.200.2

R1(config)#

お手数をおかけしてしまい申し訳ありません。
以上、宜しくお願いします。