Which one of the following correctly represents the variation of electronegativity (EN) with atomic number $(Z)$ of group 13 elements?

For group 13 elements, electronegativity decreases from B to Al. The decrease in electronegativity from $\mathrm{B}$ to $\mathrm{Al}$ is due to increased size of Al. The remaining three elements are more electro negative than $\mathrm{Al}$ and their electroonegativity increases from Ga to TI. Thus, the correct order of electronegativity of group 13 elements are as follows.