Statement I : BCl₃ and AlCl₃ are both Lewis acids and BCl₃ is stronger than AlCl₃
Statement II : H₃BO₃ is strong tribasic acid

III_A group trihalides are lewis acids as they accepts the electron pair from electron pair donors

The electron pair accepting tendency of trihalides is due to the presence of empty p-orbital in its valency shell.

I) As the size of central atom increases,

metallicnature increases,

electronegativity decreases,

and hence electron pair accepting tendency decreases,

Lewis acidic streangth decreases.

Hence acidic strength order of III_A group trihalides: Bcl₃ > AlCl₃ > GaCl₃ > InCl₃ > TlCl₃

II)

H₃BO₃    is not a protic acid and hence it is not a tribasic acid ,H₃BO₃  is a Lewis acid and the released proton is not from H₃BO₃ and the H⁺ ion is released from water.

    Therefore statement-I is true and II is false.