A. kept up
Feedback keep from - 1. to prevent 2. to hide something.
keep up - 1. to continue 2. to go as fast as someone next to you 3. to succeed 4. to be up to date/to be aware of actual information on some subject.
keep on - 1. to continue 2. to do repeatedly especially something annoying.
keep in - 1. to make somebody stay in hospital because of their health 2. to make somebody stay at home as a punishment