D. Both the intake valve and the exhust valve are closed.
The answer would be D. Infinite
Half Tens is a way of multiplying where we have to find the value of given numbers. First we double any 'one' of the two given numbers and multiply both to get an answer. Then we divide that answer by '2' to get the answer.
Lets take two numbers as 16 and 340

Double the number 16

Now we will divide this by 2

So, if we check
, it is 5440.
Similarly if we double the number 340, we get 680
Now, 
And 10880/2 = 5440
Hence, in both ways the answer is 5440.
<span>90 hundreds = 90 x 100 = 9000 Number of thousands in 9000 = 9000/1000 = 9</span>