Im not 100% sure, but I would say that the answer is A. because the magnet must be strong enough to hold the switch in place, and keep the circuit connected
Pattern P:
40, 38, 36, 34, 32, 30, …
Pattern Q:
40, 36, 32, 28, 24, 20, …
(absolute) Differences in corresponding terms:
0, 2, 4, 6, 8, 10, …
and these differences agree with the last statement.
Its either A or B because the numbers are const but there also increasing hopes this helps
Given:
Number of times Jenna feeds her cat = 2
Cat food each time 
Number of days = 5
Number of cans she bought = 8
To find:
Did Jenna buy enough cat food.
Solution:
Required food for each time 
Jenna feeds her cat twice a day.
Required food for a day 

Required food for 5 days 


Since, 7.5 cans < 8 cans, therefore, Jenna buy enough cat food for her cat.
400*9 = 3600
3600 + 450 = 4050 :)