A shopkeeper repays a short-term loan in 12 monthly instalments that form an arithmetic progression. The first instalment is Rs 2,000 and each instalment is Rs 150 more than the previous one. What is the total amount (in rupees) paid back after 12 months?
(a) 34,800
(b) 33,900
(c) 30,250
(d) 36,000