Translation:How many kinds of computer networks are there?
This sentence does not make sense. It would need to be How many kinds of computer networks are there?
"The computer network" in this sentence implies that there is a singular network that somehow has plural types. If this is not what the sentence means the definite article is unnecessary and, actually, wrong.
Drop "the" to make the sentence correct in English. "How many kinds of computer network are there?
I think because of the hard downward tone. I've noticed in the north, it tends to be harder, and often seem to include almost a glottal stop.
The comment section gets confusing when posts here may be from translation to Vietnamese, translation to English and multiple choice. Multiple choice sometimes uses new words and people may wonder what they are talking about here. I don't know if changes were made in other posts or it involves one of the three sources.