Urgent: Parents on B2 re-visiting in 5 months

[1978bubun]

My in-laws were in US for 5 months, then went back to India on Dec 1, 2016. They are coming here again on April 22, for another 5 months.

Do you guys expect any problem at the port of entry (due to "frequent" visits)? If so, what should be a good answer to that?

Thanks in advance for any help!

Bubun

[1978bubun]

Also, if anybody had their parents coming back in less than 6 months time, please share the story on what was asked.

Thanks,
Bubun