Bacteria adopt different strategies to evade host defense mechanisms. From the lists of various different mechanisms and bacterial -strategies against host defense given below, select the option representing all correct pairing.

Host defense mechanism		Bacterial strategies against host defense
a.	Phagocytosis	W.	Change of bacterial surface charge, making it more positive
b.	Release antibodies, like IgG	X.	Capsular poly- saccharides, such as that of Klebsiella pneumoniae
c.	Antibody- mediated agglutination	Y.	Release of soluble proteins like protein A of Staphylococcus aureus
d.	Anti- microbial peptides	Z.	Secretion of elastase to inactivate C3a and C5a