Why did oceans not exist on earth nearly 4 billion years ago?
a. no water molecules were present.
b. water remained a gas because earth was very hot.
c. water existed as ice because earth was very cold.
d. there was no oxygen gas in the atmosphere

think its the third option

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west