Pick the right punctuation mark at the end of the sentence.
Why did you forget to buy the milk
?

(Explanation: Since the given sentence is a question, the correct punctuation mark to use at the end of the sentence is a question mark "?".)
Complete the following task based on the instruction and optional input provided.### Instruction:
Pick the right punctuation mark at the end of the sentence.

### Input:
Why did you forget to buy the milk

### Output:
?

(Explanation: Since the given sentence is a question, the correct punctuation mark to use at the end of the sentence is a question mark "?".)