Answer:
B). After the second phrase.
Step-by-step explanation:
As per the question, if two prepositional phrases consecutively occur at the beginning of a sentence and linked using the conjunction 'and,' the comma(,) is required to be placed after the second prepositional phrase. This is because such phrases act as introductory phrases and do not involve a subject or verb of its own and thus, a comma is required to separate the main clause.
For example;
In the middle of the night, he got up and began crying on his bed.
In this example, the two prepositional phrases are 'in the middle' and 'of the night.' The comma is placed after the second and it conveys the meaning effectively. Hence, option B is the correct answer.