The increasing order of pKa of the following amino acids in aqueous solution is :
Gly Asp Lys Arg
(1) Asp < Gly < Arg < Lys
(2) Arg < Lys < Gly < Asp
(3) Gly < Asp < Arg < Lys
(4) Asp < Gly < Lys < Arg
Gly Asp Lys Arg
(1) Asp < Gly < Arg < Lys
(2) Arg < Lys < Gly < Asp
(3) Gly < Asp < Arg < Lys
(4) Asp < Gly < Lys < Arg