In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select ‘No Error’. I worked (1)/ as a verbal trainer (2)/ for eight months. (3)/ No error (4).?

Option 1 : 1

The correct answer is Option 1 i.e. 'error lies in the first part of the sentence.'

[ alt="bulb (3)" src="//storage.googleapis.com/tb-img/production/20/09/bulb%20%283%29.png" style="width: 40px; height: 40px;">According to rule, With time reference in which the preposition 'For,' we use the present perfect tense.
Hence, Instead of using 'worked' use 'have worked' 
Let's see an example for more clarity:
He has learned English for 1 year. (To show the completion of time we have present perfect tense.)

So the correct sentence is:
I have worked as a verbal trainer for eight months.