All real numbers that are greater than -8 and less than 8
a.-8;

(don't know what other selections are but a is definitely Out. ) 
All real numbers that are greater than -8 and less than 8 
-8<ℝ<8 
so INTEGERs wise , it includes -7~7  , i.e. -7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7
Real numbers wise it means you can put any decimals behind the integers above and it will still be included.  (ANY decimals. even 1.4142135 which is √2) 
E.g. 7.9, 6.7, -7.8, -4.3 

_Award brainliest if helped!