Explanation:

- Word: Contradict

- To contradict means to assert the opposite of a statement or belief, essentially challenging its validity.

- Option 1: Shorten

- Shorten means to make something shorter in length or duration.

- It doesn't relate to opposing or challenging a statement.

- Option 2: Refute

- Refute means to prove a statement or theory to be wrong or false; essentially to challenge and negate.

- This is similar in meaning to contradict.

- Option 3: Advise

- Advise means to offer recommendations or guidance.

- It doesn’t involve opposing or denying a statement.

- Option 4: Agree

- Agree means to share the same view or consent to a statement.

- It is the opposite of contradict.