The pressure exerted on a scuba diver at sea level is 14.70   pounds   per

Choice A is correct. It's given that the pressure exerted on a scuba diver at sea level is $14.70 \text{pounds per square inch} \left(\text{psi}\right)$. It's also given that for each foot the scuba diver descends below sea level, the pressure exerted on the scuba diver increases by $0.44 \text{psi}$. The total pressure, in $\text{psi}$, exerted on the scuba diver at $x$ feet below sea level can be represented by the expression $0.44x+14.70$. Substituting $105$ for $x$ in this expression yields $0.44\left(105\right)+14.70$, or $60.90$. Therefore, the total pressure exerted on the scuba diver at $105$ feet below sea level is $60.90 \text{psi}$.

Choice B is incorrect and may result from conceptual or calculation errors.

Choice C is incorrect. This is the pressure, in $\text{psi}$, exerted on the scuba diver at sea level, not at $105$ feet below sea level.

Choice D is incorrect. This is the rate by which the pressure, in $\text{psi}$, exerted on the scuba diver increases for each foot the scuba diver descends below sea level.