I know the answers of these questions which are D option for both of them, but I do not know why they got d. Could you show your works for me? thank you!

Use the following information for the next two questions: 110) Lucy has decided always to spend one third of her income on clothing. Lucy's income elasticity of demand for clothing is _and her price elasticity of demand for clothing is a) 1/3; -3 b) 1/3; -1 c) 1; -1/3 d) 1; -1 111). If Lucy's taste changes and she decides to spend only one quarter of her income on clothing, what are her new income elasticity of demand for clothing and price elasticity of demand for clothing? a) 1/4; -4 b) 1/4; -1 c) 1; -1/4 d) 1; -1