JACKAL AND HOWL:
Jackal and Howl are related in a specific way, and we need to find another pair of words that have a similar relationship.

COW AND MOO:
The word "cow" is related to the word "moo" in the same way as "jackal" is related to "howl." In both cases, the second word represents the sound that the first word makes.

ANIMAL SOUNDS:
Both cows and jackals are animals, and they have distinct sounds associated with them. Cows are known to "moo," which is the characteristic sound they make. Similarly, jackals are known to "howl," which is the sound they produce.

RELATIONSHIP PATTERN:
In this analogy, we are asked to find a word that represents the sound made by another animal, just like "moo" represents the sound made by a cow.

OPTIONS:
a) Caws - Caw is the sound made by a crow, not a cow. This option does not fit the analogy.
b) Hoot - Hoot is the sound made by an owl, not a cow. This option does not fit the analogy.
c) Coo - Coo is the sound made by a pigeon or a dove, not a cow. This option does not fit the analogy.
d) Moo - Moo is the sound made by a cow, just like "howl" is the sound made by a jackal. This option fits the analogy perfectly.

CONCLUSION:
Therefore, the correct answer is option 'D' - Moo. The relationship between jackal and howl is the same as the relationship between cow and moo, as both represent the sounds made by the respective animals.