Riddle

Even the oldest ones can be described as current, but a little mainstream.

Choose an answer

A.A stream
B.The news
C.A trend
D.A river
Hint: It's a 2-word phrase with 6 letters, starting with "A".

Answer

A river

Why this is the answer

A river always has a 'current' (flow of water) and a 'mainstream' (main channel) -- a clever double meaning even for the oldest rivers.

This riddle is filed under Hard/Difficult Riddles and rated Medium.