A. The police has arrested two motorcycle mechanics for their alleged involvement in innumerable vehicle thefts.
B. The police arrested two motorcycle mechanics for their alleged involvement in innumerable vehicle thefts.
C. For their alleged involvement in innumerable vehicle thefts, police had arrested two motorcycle mechanics.
D. For their alleged involvement in innumerable vehicle thefts, two motor cycle mechanics have been arrested.
✅ The correct answer is option B.