Explaination
Parasitism is where a parasite lives on some living beings and proceed to take their advantage.
Example
A parasite controls a bug's body. This is classified as a Parasitism.
A parasite sucks blood. This is also classified as a Parasitism.
Parasitism is basically one living gets the advantage while the another living gets disadvantage.
From the choice, the answer is C because the ticks live on the cow and suck their blood, giving the cow disadvantage. The cow will slowly die and if the cow dies, the ticks will find a new one or die if they don't find any livings to live on.
Answer