Read this excerpt from the poem "The Missing Books":

The thief, as clever as a fox,
Crept out the door with the full box.
Dennis yelled loudly like a train,
The thief's face showed a sudden strain
He ran. He tripped. Then, he saw
Sandra light up his guilty claws.

What does the simile as clever as a fox mean as it is used in the poem? (2 points)

a
Awkward

b
Flexible

c
Innocent

d
Sneaky