What Can We Conclude About the Encoding-Specificity Principle

What can we conclude about the encoding-specificity principle?

A) Context effects are very clear-cut, especially in laboratory research.
B) Current research suggests no evidence for the encoding-specificity principle.
C) Context effects are often demonstrated in our daily experiences, but the effect is relatively weak in laboratory research.
D) Context effects are especially prominent when the material has been well learned.