Answer: The order with respect to
is 1.
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

k= rate constant
x = order with respect to 
y = order with respect to A
n = x+y = Total order
From trial 1:
(1)
From trial 2:
(2)
Dividing 2 by 1 :
therefore x= 1
Thus order with respect to
is 1.
In order to solve this question, we must apply the conservation of mass. The total number of nucleons (upper number) and protons (lower number) must be equal before and after the decay. The new nucleon number is
218 - 4
= 214
And new proton number is
84 - 2
= 82
Next, we must identify which element has the proton number 82. That would be lead, Pb.
Therefore, the answer is
5. ²¹⁴Pb₈₂
The correct answer is "B. Make a Hypothesis".
The answer is temperature (may be wrong)