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

detailed solution

Correct option is D

IIIA group trihalides are lewis acids as they accepts the electron pair from electron pair donorsThe 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 IIIA group trihalides: Bcl3 > AlCl3 > GaCl3 > InCl3 > TlCl3II)                               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.