On many occasions (1)/ we did helped the poor (2)/ people by way of giving them food to eat and clothes to put on. (3)/ No error (4)

Answer

2

Explanation

help will replace helped because -
do/does/did (Aux. V.) is used when no other Aux. V. is Present, to emphasize what you are saying. The pattern used with do/does/did is as follows :
do/does/did + Main Verb (Base form) did + help (Base form) of help (verb) will be used.
Look at the examples given below:
He does look tired.
She did at least write to say thank you.
I do want to be sure.
Hence, we did help the poor is the right usage