Final answer:
The common ratio for the given sequence is found by dividing any term by its preceding term, leading to 1/4 as the correct common ratio.
Step-by-step explanation:
To find the common ratio of the sequence 64, 16, 4, 1, ..., we need to divide any term by the term that precedes it. For example, if we divide the second term (16) by the first term (64), we get 16 ÷ 64 = 1/4. To confirm that this is the correct common ratio, we check if the other terms follow the same pattern by dividing the third term (4) by the second term (16), which also gives us 4 ÷ 16 = 1/4. Since the same common ratio applies to consecutive terms, the correct answer is c) 1/4.