When working away from the office sales representative might typically use which type of computer ?

I think C is the correct option. A tablet or a4g smart phone would also do the job. 

Nowadays most are working with laptop, so i'd go for C.

When someone uses a computer off the office at the time of time he uses a Laptop computer . C . Option

the correct answer is C : laptop, but a tab can be an alternative solution

Basm Allah Alrahman Alrahim

- inside company desktop of course

- outside company laptop or tablet I prefer2 in one

- at the future ( God only know ) I like to use mechanical analog computer [ from terminator movie , I don't mean arnold schwarzenegger but the other terminator one!] 

Thank you for this question that help us to search and learn