Correct option is B
The most appropriate option to fill in the blank is (b) "pale."
The sentence should read: "The patient looked pale and tired."
In this context, "pale" means having a paleness or lack of color in the skin, often associated with illness or fatigue.
Meanings of the other options:
Pail: A container, typically with a handle and used for carrying liquids.
Pall: A cloth spread over a coffin, hearse, or tomb.
Peel: To remove the outer layer or skin of something, such as fruits or vegetables.