Question

It's very stuffy here. Don't worry, I ........... (open) the window for you.​

Answer 1

opened?

Explanation: maybe you didn't really explain this well.... sorry if this answer is bad

Answer 2

will

Step-by-step explanation:

It's very stuffy here. Don't worry, I will open the window for you.

Because, she hasn't opened the window yet meaning she will open the window.