Answer:
The answer is
a. 5g/mL
Step-by-step explanation:
Given data
mass m= 45g
volume v= 9mL
we know that density=m/v
substituting our given data we have

What is Density?
The Density of a body can be defined as the ratio of mass to volume,
or
Density, mass of a unit volume of a material substance. The formula for density is
,
where d is density,
M is mass, and
V is volume.
Density is commonly expressed in units of grams per cubic centimetre.