The statement: "secondary evidence is the basis for drawing scientific conclusions" is definitely false. Secondary evidence is the body of information obtained to prove the existence of unknown or missing primary evidence. In drawing scientific conclusions, primary evidence is needed.
The first one is revolves
(a) 
The moment of inertia of a uniform-density disk is given by

where
M is the mass of the disk
R is its radius
In this problem,
M = 16 kg is the mass of the disk
R = 0.19 m is the radius
Substituting into the equation, we find

(b) 142.5 J
The rotational kinetic energy of the disk is given by

where
I is the moment of inertia
is the angular velocity
We know that the disk makes one complete rotation in T=0.2 s (so, this is the period). Therefore, its angular velocity is

And so, the rotational kinetic energy is

(c) 
The rotational angular momentum of the disk is given by

where
I is the moment of inertia
is the angular velocity
Substituting the values found in the previous parts of the problem, we find

"The path difference between the two waves should be one-quarter of a wavelength" is the statement among the choices given in the question that describes the <span>path difference between the two waves. The correct option among all the options that are given in the question is the fifth statement or the penultimate statement.</span>