i am not able to answering the question, why?

Thanks to all for response! Due to not being logged in, I was not able to give answer on the Yahoo Q/A. 

What level are you on? Because sometimes it can be the level that restricts you from answering it

Either you have been blocked or your mobile device is NOT in desk top mode or there is a other technical problem, like the modem being dead because the power strip is not on.

It could be that the person who asked the question have you blocked. Also sometimes the submit tab is a very light color but it still works if you see it. Looking at your questions and answers you have not come close to using your limits for the day.

because the asker has you blocked or you've answered your daily quotum

There is a glitch with the Submit button. Refresh the page and try again. You also will not be able to post if you have reached your daily limit or you try to put a percentage sign in your posts, and you will not be able to answer questions if an asker has you blocked.

There could be a few reasons:

1 - you reached your answer limit for the day and have to wait until the new YA day (you can answer 120/day)

2 - the question(s) you're attempting to answer are posted by a user or users who have you blocked

3 - you're looking at questions in the list under the "Discover" tab, not the 'Answer' tab. The Discover questions are older, and often closed to new answers.

did you reach your daily limit ? yahoo has a limit on the number of questions you can answer a day if you see the word in red false that means you reached your limit for the day and you have to wait til 8:00 pm pst pacific standard time when everything resets again for the next day

beacuse you dot about it thats why