Had the plane not been delayed, (1)/ I will reach here (2)/ in time for the function. (3)/ No error (4)

Answer

2

Explanation

If the tense in the Conditional Clause is in Past Perfect, the tense in the Main Clause is in Perfect Conditional
Look at the examples given below:
`{:("If it had rained, you would have got wet."),(" "darr " "darr),("Past Perfect"" Perfect"),("Tense "" Conditional"):}`
Hadyou worked hard, you would have passedyour exam.
Hence, I would have reached here is the right usage.