Decode the following TAF: OVC012 BECMG 1416 BKN020
a) Overcast sky at 12, becoming broken sky at 14:16 Zulu
b) Becoming overcast at 12, broken sky at 14:16 Zulu
c) Overcast sky at 12, becoming overcast sky at 14:16 Zulu, broken sky at 20
d) Overcast sky at 12, becoming broken sky at 14:16 Zulu, becoming overcast sky at 20