Why isn't R = B - D or R = A + C correct for this vector diagram?

[Beanie]

Homework Statement

Express the vector R in terms of A, B, C, D
(VIEW IMAGE ATTACHED)

Homework Equations

The Attempt at a Solution

R=B-D
OR
R=A+C

In this problem, I figured that because of the way the arrows are pointing R+D=B which you can then simplify to R=B-D. However, this is not an answer to the problem.

I then tried using the other triangle with R. Because of the way the arrows are pointing, I figured that A+C=R. However, this is also not a solution to the problem.

 

[phinds]

R=B-D
OR
R=A+C

I agree. What is the stated answer?

 

[Beanie]

I agree. What is the stated answer?

There is no stated answer, however these are the possible answers (VIEW ATTACHED IMAGE)

 

[phinds]

Right. And one of those works just fine.