B1
a very tall, narrow building, or part of a building
Dictionary examples:
I got lost in the office tower and ended up in the CEO's bathroom! (0.0)
The pizza delivery guy climbed 50 floors of the tower because the elevator was broken. (0.0)
The new office tower looks like a giant banana standing on its end. (0.0)
the Eiffel Tower (3.8)
He works in an office tower in downtown San Francisco. (27.0)
There's a clock on the church tower. (27.0)