Leon Company's city center plant recently hired a second shift of employees who manufacture the product Plumbo. (The second shift works from 4 p.m. to midnight after the first shift is finished, which doubles the total plant capacity.) Information about the cost of labour in the previous month is as follows: The labour rate variance at the city centre plant in the previous month was: a. $13,200 unfavourable b. $15,500 unfavourable c. $13,200 favourable d. \$15,500 favourable