Explanation:

- The sentence is about enduring something that is difficult or painful.

- Option 1: Bier

- A "bier" is a frame or stand on which a coffin or corpse is placed before burial.

- It's unrelated to enduring pain.

- Option 2: Boor

- "Boor" refers to a rude or insensitive person.

- It doesn't relate to the context of pain.

- Option 3: Bear

- "Bear" means to carry or endure something difficult or painful.

- This is the correct option for enduring pain.

- Option 4: Beer

- "Beer" is a beverage.

- It's not relevant to enduring pain.