Answer:
correct option is c. Walls
Step-by-step explanation:
solution
we know that Form tie is use for the connecting an opposite wall face of form work.
it is help to restraining an excess pressure of concrete and it is transfer concrete load in tension form between the horizontal element and vertical element that associate with form work
and generally its length range from 210 mm and 250 mm and 300 mm
so correct option is c. Walls