Parents visa denied on the basis of age

[vimi]

Hi All,
My parents gave US visitor’s visa interview for the second time few days back and they were denied visa on the basis of old age this time. Do any of you have any clue about it? Is there any age limit for applying visitor’s visa for US? I just want my parents to come here once and see few places. I felt very disappointed because they might be feeling the same. My father is 76 and my mother is 68 years of age. I really don't know what to do and when should I reapply for the third round. Please reply if you have any suggestions or have faced similar situation or know about it.
Many thanks.

[immihelp]

That seems very unlikely to be the case.

So many Indian visitors come to the U.S. who are of that age.