IUPAC name of the some alkenes are given below. Find out the...

The stability of alkenes is directly proportional to the number of $\alpha$-hydrogen atoms due to hyperconjugation.

Let us count the number of $\alpha$-hydrogen atoms in each given alkene:

A. 2-Methylbut-2-ene: $(CH_3)_2C=CHCH_3$
Number of $\alpha$-hydrogen atoms = $3 + 3 + 3 = 9$

B. cis-But-2-ene: $CH_3CH=CHCH_3$
Number of $\alpha$-hydrogen atoms = $3 + 3 = 6$

C. 2,3-Dimethylbut-2-ene: $(CH_3)_2C=C(CH_3)_2$
Number of $\alpha$-hydrogen atoms = $3 + 3 + 3 + 3 = 12$

D. Prop-1-ene: $CH_3CH=CH_2$
Number of $\alpha$-hydrogen atoms = $3$

Since the stability of an alkene increases with the number of $\alpha$-hydrogen atoms, the correct stability order is C > A > B > D.

Answer: C > A > B > D