Select the most appropriate option to fill in the blank.
Just bite the ............. and tell him the truth.

The correct answer is bullet.

Explanation:
The sentence is based on a common English idiomatic expression: "bite the bullet".
This idiom means to face a difficult, painful, or unpleasant situation with courage and endurance, especially one that has been delayed or avoided.

Let's look at the context of the sentence:
"Just bite the ............. and tell him the truth."
Telling someone a difficult truth is often unpleasant or nerve-wracking, which fits the meaning of facing a tough situation head-on.

Why other options are incorrect:
- "shot" or "gun" do not form any standard idiomatic expressions with "bite".
- "bite the dust" is a common idiom, but it means to fall dead, fail, or be defeated (e.g., "Another one bites the dust"). It does not fit the context of confronting a difficult situation or telling the truth.