In Which One of the Following Cases Has Communication Occurred

Multiple Choice

In which one of the following cases has communication occurred?

A) Gary updates his blog regularly, even though no one reads it.
B) Brian attends all the Algebra lectures, but is unable to understand the subject.
C) Jen has sent an urgent e-mail to her Japanese colleague, but a translator is not yet available.
D) Ana tells her manager that she needs a new computer, but he says that the company can't afford it.