question_answer

Let \[{{n}_{1}}<{{n}_{2}}<{{n}_{3}}<{{n}_{4}}<{{n}_{5}}\] be positive integers such that \[{{n}_{1}}+{{n}_{2}}+{{n}_{3}}+{{n}_{4}}+{{n}_{5}}=20\]. Then, the number of such distinct arrangements \[({{n}_{1}},\,\,{{n}_{2}},\,\,{{n}_{3}},\,\,{{n}_{4}},\,\,{{n}_{5}})\] is________.

A)  3                                            

B)  5

C)  7        

D)  9

E)  None of these