Easy grammer !

which sentence is correctly punctuated? (11 points)

a)a barking dog is perhaps the biggest annoyance; however, few dog owners train their dogs to hush.

b)along came the cat in pouncing position to launch at the bird: clueless of its surroundings.

c)there was never a threat before as striking as this one but for the one on march 1st.

d)taking lessons from the predator: the prey is the most important thing.