Knowledge: Prepositions
Explain:
A. whose + N + V: … of something (used to replace the possessive word, acting as the subject)
B. that + V: something/person that (used to replace nouns indicating things/people, acting as the subject)
C. where + S + V: where (= preposition + which, used to replace place words, acts as an object)
D. which + V: what (used to replace the noun of the object, acting as the subject)
… many of the best views of Mount Fuji are from these lakes, (49) whose still waters reflect the mountain’s beautifully symmetrical outline like a mirror.
=> Many of the best views of Mount Fuji come from these lakes, whose calm waters reflect the mountain’s beautiful symmetry like a mirror.
Choose A.