Glucose on prolonged heating with HI gives

The predominant form of histamine present in human blood is (pK_a, Histidine = 6.0)

An alkali is titrated against an acid with methyl orange as indicator, which of the following is a correct combination?

Two sets A and B are as under :

A = {($$a$$, b) $$ \in $$ R $$ \times $$ R : |$$a$$ - 5| < 1 and |b - 5| < 1};

B = {($$a$$, b) $$ \in $$ R $$ \times $$ R : 4($$a$$ - 6)² + 9(b - 5)² $$ \le $$ 36 };

Then