Marta is the subject of the sentence because she is performing the verb "Planned"
Answer:
B is the answer okkkkkkkkkkkkkkkk
The correct answer should be additionally.
The word additionally would provide the best transition between these two sentence. It is so because you have one idea in the first sentence, and then you want to show another idea very similar to the first one in the second sentence. Using additionally to convey that is the way to go.
