Which of the following is an incorrect pair regarding Bentham and Hooker's classification of Polypetalae?

In an astronomical telescope in normal adjustment,a straight black line of length $L$ is drawn on the inside part of the objective lens. The eyepiece forms a real image of this line. The length of this image is $I$. The magnification of the telescope is:

The extreme values of $4 \cos \left(x^2\right) \cos \left(\frac{\pi}{3}+x^2\right) \cos \left(\frac{\pi}{3}-x^2\right)$ over $\mathbb{R}$ are

The condition that $f(x)=a x^3+b x^2+c x+d$ has no extreme value,is

Pepsin is inactivated at $pH$

The major product in the following reaction is: