Explanation:

The correct option to fill in the blank is "no article, no article" (option C).

Explanation:

In this sentence, we are talking about child development in general, without specifying any particular child development or universities. Therefore, we do not need to use any articles before "child development" or "universities."

Articles:

Articles are used to specify or indicate the noun they precede. There are three articles in English: "a," "an," and "the."

- "A" and "an" are indefinite articles and are used to refer to a non-specific noun.
- "The" is a definite article and is used to refer to a specific or particular noun.

Usage of Articles:

- "No article" is used when we are talking about general or non-specific things or ideas.
- "The" is used when we are talking about specific or particular things or ideas.

Application to the Sentence:

In the given sentence, we are talking about child development in general, not a specific child development. Therefore, we use "no article" before "child development."

Similarly, we are talking about universities in general, not any specific universities. Therefore, we use "no article" before "universities."

Example:

- Many people are studying child development at universities all around the world.
- Many people are studying the child development at the universities all around the world.
- Many people are studying a child development at the universities all around the world.

In the above examples, the first sentence (option C) is the correct one because it conveys the general idea of studying child development at universities without specifying any particular child development or universities.

The second sentence (option B) uses "the" before both "child development" and "universities," indicating a specific child development and universities, which is not intended in the sentence.

The third sentence (option D) uses "a" before "child development," indicating a singular and specific child development, which is also not intended in the sentence.

Therefore, the correct option is "no article, no article" (option C).