David, ping, mandy, and alan are each studying one of the animals shown in the table for a science project.
animal study project
animal
speed
type
habitat
elephant
25 mph (running)
mammal
grasslands
sailfish
68 mph (swimming)
fish
oceans
giraffe
32 mph (running)
mammal
grasslands
dolphin
30 mph (swimming)
mammal
oceans
source:

david is studying a mammal, but ping is not. the animal that mandy is studying can be found in the ocean. the animal that alan is studying is slower than the animal that david is studying.
who is studying the dolphin?
a.
ping
b.
mandy
c.
david
d.
alan