Adjectives

Hi there

I am stuck on this question. Not sure if is written incorrectly, and that the blank space should precede the word "horse". Please note it is an "adjective" question as this is how it has been assigned in my book.

Fill in the blank space with a suitable describing word:

The horse ( ) drank deeply at the trough.

My answers:

There are two choices:

1. If the blank space is after the word "horse", then we would need to use an adverb, such as "thirstily".

2. If the blank space were to precede the word "horse", then we could use an adjective, such as "parched".

However, I am assuming that the question is printed correctly, and that an "adjective" is required after the word "horse".