The underlined word "boost” in the last paragraph means

A．It improves problem-solving skills and creative thinking.
B．It helps you do your best in school.
C．It helps your brain sort out information from your day.
D．It has a good rest.

A．Because it's easier to buy a baby dog under three months.
B．Because they are less likely to be shy with human being.
C．Because they are less likely to run away.
D．Because it's easier for them to form a relationship with their masters.