Answer : 3. "Good news is expected by us about the corona vaccine."
Explanation :

The given sentence is in an active voice form, hence we need to convert it into a passive voice form.
We need to follow these instructions while changing the voice of an assertive sentence.
Find the subject (We) and object (good news) of the sentence and exchange their places.
The given sentence is in the present indefinite tense.
The passive verb form for the present indefinite sentence: is/are + V3 + by + subject.
So, 'expect' changes into 'is expected'.
At last line up the remaining part.
Following this structure, we get the 4th option as the correct answer.  
Following these steps, we finally get- Good news is expected by us about the corona vaccine.