"i need use ,,block,, shape (C) in storyline 3, but in storyline 3 (A) drop in (B) when (C) is not hidden, I can not use (C) as ,,block,,"

"hi, in  Storyline 2    front  shape  don't let  object  drop in target,  but  in storyline 3 object  drop  in target when   when ,,blocke..."

"hi, in storyline 3 I insert 3 shapes, lets name it A,B and C, for example in A set trigger ,,play media true when A drop in B,, but I set..."