Is it obligatory to be multilingual?

Is it obligatory? No, you are not required to become multilingual. Therefore the alternate option is false, because in the U.S. it is not obligatory. However, I think it's a great idea to become multilingual. Some people don't want to, and that's fine. It will just be harder for them to communicate with other people in other countries, if they decide to travel around. But, of course, not everyone does, so why should it be mandatory? America is an English-speaking country, has been, and hopefully will always be. If I am an immigrant, I should learn English in the U.S., as I would if I immigrated to another foreign-speaking country. But The poll is not asking about immigrants. I assume it applies to everyone in the U.S. since there is a U.S. flag as the photo of the "No." option, so that being the case, I would say no, it shouldn't be. People should have the freedom to do what they want, as long as they don't hurt anyone else. Case closed.

NO, it is affable.

Beneficial, yes, but I don't think it's really going to make THAT much of a difference if you're not

No but is should be something people are open to. We live in a world with many languages; the diversity of knowing foreign languages in some places will give you an edge over competitors for jobs. Like learning spanish in America if you live in Texas or anywhere, where there is a lot of spanish speaking people.

The world may be getting smaller and English may be the new-age lingua franca but a lot of regional languages have held on to their script and communication medium. Something that is not lost on software/app makers, publishers et al. The more languages you know, the greater ease you will have in conducting business, building relations with them. I know this out of personal experience.