The correct answer is B. Photograph: picture
In analogies, it is required to apply the type of relationship found in a pair of two elements or concepts into a new pair of elements establishing in a relationship of analogy or comparison. This means, in this case in which the original pair of concepts is “phase: stage” that relate to each other as synonyms because they both refer to a section in a process, the pair of words that complete this analogy also need to be synonyms or have similar meanings.
Considering this, the pair of words that relate to each other as synonyms and therefore can complete this analogy are “photograph: picture” because they both refer to an image of an object, person or animal that can be produced by using a camera, which means as “phase” and “stage” these concepts are synonyms and therefore a similar relationship or analogy is established between both word pairs.