A speaker can combat the problem of the audience's limited attention span by:.
a. using lots of sound bites.
b. employing a minimum of supporting material.
c. dividing the speech into small segments.
d. over-simplifying the message.
e. ending the speech at the first sign of boredom.

c. dividing the speech into small segments.

Explanation:

Good speaker have to combat few problems, like audience lose interest after some time. As audience feel bore so speaker must use some strategies to engage audience in his speech so dividing the long speech into small segments make people feel alert and awake. It means to divide and make parts of your topic, so audience feel fresh and attentive to listen all segments, as audience feel change after moving next segment.

i got 3,4 and 5 as an answer