A.) reference group
"A reference group includes individuals or groups that influence our opinions, beliefs, attitudes and behaviors. They often serve as our role models and inspiration"(study.com).
First, foremost, and most critically, you must look at the graph, and critically
examine its behavior from just before until just after the 5-seconds point.
Without that ability ... since the graph is nowhere to be found ... I am hardly
in a position to assist you in the process.
The direction of the electric field would be south.
qE/m = 115
<span> E = 115*m/q </span>
<span> = 115 * 9.1 * 10^(-31) / 1.67*10^(-19) </span>
<span> = 762.87 * 10^(-12) </span>
<span> = 6.27 x 10^-10 N/C
</span>
Hope this answers the question. Have a nice day. Feel free to ask more questions.