Correct option is B
- The sentence describes a past situation, so the past tense remained is appropriate.
- The country name Netherlands generally takes the article the (the Netherlands), while Germany does not take the.
- Option (b) correctly uses remained and the proper article usage: the Netherlands and Germany.
- (a) Uses present tense remains and incorrectly says the Germany.
- (c) No correction required is wrong because the original lacks the before Netherlands.
- (d) Uses present tense and also misses the before Netherlands.