Which of the following elements of group $15$ $(VA)$ does not show allotropy?

Given below are two statements:
Statement $I$: Like nitrogen that can form ammonia,arsenic can form arsine.
Statement $II$: Antimony cannot form antimony pentoxide.
In the light of the above statements,choose the most appropriate answer from the options given below:

Among the oxides of nitrogen $N_2O_3$,$N_2O_4$,and $N_2O_5$,the molecule$(s)$ having nitrogen-nitrogen bond is/are

Which form of phosphorus is thermodynamically most stable?

The oxoacid of phosphorus having the strongest reducing property is

Select the correct statement.