Question

What does it mean to be as soft as silk?

a. very soft (The cover of my new book is as soft as velvet)
b. very black (The pirate's evil eyes are as black as coal)
c. very soft or gentle (The singer's sweet voice sounded as soft as silk)
d. very smooth (He washed his face until it was as smooth as glass).

Answer 1

Must be soft it doesn't have to be smooth

Answer 2

A. Very soft. Silk is soft. It's not necessarily black, doesn't sound like anything, and doesn't have to be very smooth.