Hybridisation of boron in diborane is

Diborane reacts with ammonia under different conditions to give a variety of products. Which one among the following is not formed in these reactions?

Identify the correct statements from the following:
$(a)$ In orthoboric acid, boron is in planar geometry.
$(b)$ In $BCl_3 \cdot NH_3$, boron has tetrahedral geometry.
$(c)$ Aqueous solution of borax is acidic.

If the formula of Borax is $Na_2B_4O_x(OH)_y \cdot zH_2O$,then $x+y+z = ...........$.

The correct statements from the following are:
$(A)$ Ionic radii of trivalent cations of group $13$ elements decrease down the group.
$(B)$ Electronegativity of group $13$ elements decreases down the group.
$(C)$ Among the group $13$ elements, Boron has the highest first ionisation enthalpy.
$(D)$ The trichlorides and triiodides of group $13$ elements are covalent in nature.
Choose the correct answer from the options given below:

Which of the following statements is not true?