At a party, it's sometimes permissible for serving personnel to
a. smoke, provided they don't do so in view of the guests.
b. become part of the party if they know some of the guests.
c. take home any leftovers that remain.
d. sample the buffet items before the guests arrive.

At a party, it's sometimes permissible for serving personnel to sample the buffet items before the guests arrive. The answer is letter D. This is to ensure that the food they are serving will fit with the taste of the guests.

The correct answer is letter A. At a party, it's sometimes permissible for serving personnel to smoke, provided they don't do so in view of the guests. There are designated areas where people are allowed to smoke because we can not really deny and avoid that there are people who really wanted to smoke.

Explanation: I think you need to read the article