Whose skateboard is this?
'It's mine, Alex!' said Bart. 'And my sister Lisa's bike is over there.'
'Okay, and whose ball is that?' asked Alex.
'That's our friend Milhouse's ball,' replied Bart.
A) It's Bart's skateboard.
B) It's Alex's skateboard.
C) It's Lisa's skateboard.
D) It's Milhouse's skateboard.