In the following question, one part of the sentence may have an error. Find out which part of the sentence has an error and click the option corresponding to it. If the sentence is free from error, click the 'No error' option. DNA evidence can be useful  (P) / as a forensic tool but it is not (Q) / a silver bullet to solving every crime (R) / No error (S)?

Option 3 : R

The error lies in the part R of the sentence. Thus, the correct answer is option 3.

Silver bullet means a simple magical solution to a difficult problem.

As the -ing form of the verb solving is used, the correct preposition in the part R is for and not to.

Correct sentence - DNA evidence can be useful as a forensic tool but it is not a silver bullet for solving every crime

Tip – A general thumb rule followed in English is :

for  +   verb in its ing form (for eating, for dancing)

to  +  verb in simple present tense (to eat, to dance)