【正确答案】 C

【答案解析】[解析] 画线词组in the end为副词词组，意为“最后，最终”。C项ultimately意为“最后，根本上”；与画线词意思相近；例：I believe we are ultimately going to be successful.我相信我们最后终将成功。A项undoubtedly意为“确实地，毋庸置疑地”；例：It has undoubtedly led to many exciting developments.它的确导致了许多令人兴奋的进展。B项certainly意为“当然，必定”；例：I"m certainly going, but I"ll be a little bit late.我去是去，可是得晚一点儿。D项necessarily意为“必要地，必然地”；例：A higher fee doesn"t necessarily mean a better course.收费更高并不意味着课程就一定好。故本题选C。