C-09-Q079mediumsingle_mcqWhich of the following is a base?aH2SO4\mathrm{H_2SO_4}H2SO4bHCl\mathrm{HCl}HClcCu(OH)2\mathrm{Cu(OH)_2}Cu(OH)2dHNO3\mathrm{HNO_3}HNO3