When a speaker divides a speech into subtopics, he or she is actually following a __________ in the speech.
A: chronological order
B: spatial order
C: topical order
D: problem-solution order
选项：
A chronological order follows a time pattern. When a speaker explains a process or demonstrates how to do something, he or she usually adopts a chronological order. 
B:Topical order results when a speaker divides the speech into subtopics, each of which becomes a main point in the speech. 
C:Speeches arranged in problem-solution order are divided into two main parts. The first shows the existence and seriousness of a problem. The second presents a workable solution to the problem. 
D:Speeches arranged in spatial order follow a directional pattern.