The correct option is B for
Option A - 'About' means 'regarding'. For example, 'I was talking about Economics.' The 'places' in the sentence are not regarding 'pilgrimage'. Thus option A is incorrect.
Option C - 'Of' is used to explain 'possession' and 'relating'. The sentence doesn't talk about possession and hence we can't use 'of' here. Thus option C is incorrect.
Option D - 'From' is used to explain the starting point of a person, thing or a location. As 'pilgrimage' isn't the starting point of 'places' we can't use 'from' here. Thus option D is incorrect.
Option B - 'For' is used to explain the purpose. People visit the places with the purpose of pilgrimage and hence we can use 'for' here. Thus option B is the correct answer.
'Indians who have great faith in 'God' visit these places for pilgrimage.'