A consumer allocates his expenditure between three goods, X, Y and Z.

The table shows the consumer's marginal utilities for these goods and their prices.

good X Y Z

marginal utility (units) 50 30 25

price ($) 20 15 10

How should the consumer's expenditure be reallocated in order to maximise his utility?

X Y Z

A more more less

B more less more

C less more less

D less less more