Question

According to pronunciation guides in the dictionary, what letter is regarded as both a vowel and a constant

A. B

B. E

C. O

D. Y

NVRM it's D. Y

Answer 1

Out of 26 letters we have 5 vowels: A, E, I , O, U
Y, is considered as the sixth vowel because it can sound like another vowel.

Answer D

Answer 2

You are correct in saying that it is y, for instance pygmy.