Firm A faces a price elasticity of demand of -2.5 and a cross-price elasticity of demand with Firm B's product of 0.75. If Firm B leaves its price unchanged when Firm A lowers its price by 5%, then the change in Firm A's quantity sold will be

a)a fall of 25%

b) a fall of 12.5%

c)a rise of 12.5%

d)a rise of 25%