Final answer:
Keiko possessed both a sketchbook and a tiny frame, with the frame containing a sketch of her and Henry, making the answer both a and b.
Step-by-step explanation:
Based on the context given in the question, it seems that Keiko had both a sketchbook and a tiny frame with a sketch of Henry and Keiko. Therefore, the answer would be (c) Both a and b. Keiko's sketchbook presumably would contain various sketches, possibly including drawings of Henry. Additionally, the tiny frame mentioned seems to be a sentimental item that has a particular sketch of both Henry and Keiko, indicating a personal connection or relationship between the characters in question.