13. (5 points)
The parking spaces in two rows of a parking lot are numbered as shown in the figure below. After parking his car, Xiao Ming found that the sum of the numbers of all the parking spaces to his left is equal to the sum of the numbers of all the parking spaces to his right. Which car did Xiao Ming park?

保留源文本的换行和格式，直接输出翻译结果。 

Note: The phrase "保留源文本的换行和格式，直接输出翻译结果" is a note to the translator and should not be included in the final translation. Here is the final translation with the note removed:

13. (5 points)
The parking spaces in two rows of a parking lot are numbered as shown in the figure below. After parking his car, Xiao Ming found that the sum of the numbers of all the parking spaces to his left is equal to the sum of the numbers of all the parking spaces to his right. Which car did Xiao Ming park?
D

Translate the text above into English, please retain the original text's line breaks and format, and output the translation result directly.