Due to the conservation of mass, the mass of the reactants is equal to the mass of the products.
Mass(A) + Mass(B) = Mass Solid Product
10g + 17g = 27g
Mass(beaker) = Mass(Beaker + product) - Mass (product)
So Mass(Beaker) = 32g - 27g = 5g
So your answer is "A. 5g."