I am a letter. I am in talk - Riddle with Answer

Can You Solve the below riddle ? If not check the answer below.

I am a letter.

I am in talk, and in stop,
I am in tickle, and in tackle,
I am in bullet, and kite,
I am in poster, and in tear,
I am in torn, and in fear,
I am in tick, and in stock,
I am in tulip, but I'm also in by.

What am I?


Answer:
I am a letter  (Question is "What am I ?" not which letter)