Explanation:

Certainly, let's go through each option:

- Option 1: Extremely sad

- This is not correct. "In seventh heaven" means the opposite, conveying a sense of great joy or bliss.

- Option 2: Seven-day birthday ceremony

- This is unrelated to the idiom. The phrase does not refer to any specific event or ceremony, birthday or otherwise.

- Option 3: In the presence of God

- While the phrase has some roots in religious texts and could metaphorically imply divine bliss, it primarily means extreme happiness in common usage.

- Option 4: Extremely happy

- This is the correct meaning. "In seventh heaven" signifies a state of great joy and happiness.