Fill in the blank with the most suitable option from the words given below.

The students ______ came late to the class, have missed out on some important concepts.

who

The correct answer is Option (1) - who

• The blank refers to "The students", which are people.
• "Who" is used for people when functioning as the subject of the clause.

Thus, the correct sentence is:
"The students who came late to the class have missed out on some important concepts."