The correct answer is a descriptive investigation.
An investigation which does not involve hypotheses called descriptive investigation.
Hypotheses are termed as scientific hypotheses and require that one can test it. In hypothesis, previous observation can not satisfactorily be explained with an available scientific theory.
Working hypotheses are being proposed for further research.
- The answer is shorter wavelength and equal speed.
That is, compared to ultraviolet light, an electromagnetic wave that has a higher frequency will also have shorter wavelength and equal speed.
This can be seen by the reaction given below:

h= Planck's constant
c=speed of the light
=frquency
=wavelength
So, higher is the frequency, lesser is the volume while speed remains constant as c is speed of light.
30 because it is the highest number of marriage
Answer:
answer is c
Explanation: cause there breaking it