Fill up the blank with the right option from below.
Raju _______ his wife to tell her that he could be home late.

Call up" is often used in informal speech when referring to making a phone call.
Example: "He called up his friend to discuss the meeting."
Why not other options?
"Called" (Option 1)

While "called" can also mean making a phone call, "called up" is more commonly used in this context for informal conversations.
Example: "I called up my mom to check on her."
"Called to" (Option 3)

"Call to" is used when someone shouts or addresses someone loudly, not for phone calls.
Example: "He called to his friend across the road."
"Called on" (Option 4)

"Call on" means to visit someone or formally request them to speak.
Example: "The teacher called on John to answer."
Additional Information:
"Call up" is often used in American English for making a phone call.
Example: "She called up her sister to ask about the trip."
"Call on" is used when visiting someone or formally addressing someone.
Example: "I called on my professor to ask about the assignment."