Which among the following vitamin contains metal in it?

Which among the following vitamin contains metal in it?
A.vitaminB1
B.vitaminB2
C.vitaminB5
D.vitaminB12

A peculiar odour found in marshy areas and cow sheds is of gas produced by
a) Archaebacteria
b) Cyanobacteria
c) Slime Mould
d) Mycoplasma