To answer this question, we need to identify the pattern in the given letters "q w e r t y _" and determine the missing letter.
The given letters are the first six letters on the top row of a standard QWERTY keyboard. The next letter on the keyboard after "y" is "u". Therefore, the correct answer is:
Option A) u - This option is correct because it is the next letter on the QWERTY keyboard after "y".