ind next number in the series
23 21 24 19 26 15 28 11 30 7 36 ?
Options:  A) 12  B) 20  C) 5  D) 40  E) 34
C   5   23-2= 
<gadget id="calculator">23-2</gadget>
<output>21</output>
21   21+3= 
<gadget id="calculator">21+3</gadget>
<output>24</output>
24   24-5= 
<gadget id="calculator">24-5</gadget>
<output>19</output>
19   19+7= 
<gadget id="calculator">19+7</gadget>
<output>26</output>
26   26-11= 
<gadget id="calculator">26-11</gadget>
<output>15</output>
15   15+13= 
<gadget id="calculator">15+13</gadget>
<output>28</output>
28   28-17= 
<gadget id="calculator">28-17</gadget>
<output>11</output>
11   11+19= 
<gadget id="calculator">11+19</gadget>
<output>30</output>
30   30-23= 
<gadget id="calculator">30-23</gadget>
<output>7</output>
7   7+29= 
<gadget id="calculator">7+29</gadget>
<output>36</output>
36   36-31= 
<gadget id="calculator">36-31</gadget>
<output>5</output>
5   (2,3,5,7,11,13,17,19,23,29,31,37,41,43... are Prime Numbers)
<result>C</result>
ind next number in the series
23 21 24 19 26 15 28 11 30 7 36 ?