I don't know if their is sopposed to be options but my best educated guess is "Natural"
I'm gonna have to go with no
Excretory system and urinary system are both working to remove waste in the human body. but technically, urinary system is part of the excretory system. The excretory system includes the kidney organ which is the main and the most important organ of the urinary system, another part of the excretory systems are the large intestine and the lungs. on the other hand, urinary system aside from kidney includes ureters, urinary bladder and the urethra. when the human body produces waste products, both the excretory and the urinary work together to remove these waste products from the human body.
<u>Answer:</u>
<em>
heat is released by the combustion of
of methane</em>
<u>Explanation:</u>
The value of enthalpy determines whether the reaction is exothermic or endothermic. If the enthalpy change is positive, then the reaction is endothermic (heat or energy released) and if the enthalpy change is negative then the reaction is exothermic (heat or energy absorbed).

=![2 ( -(393.5 KJ)/mol)-[2( -74.6 KJ/mol)+4(-241.82 KJ/mol)]](https://tex.z-dn.net/?f=2%20%28%20-%28393.5%20KJ%29%2Fmol%29-%5B2%28%20-74.6%20KJ%2Fmol%29%2B4%28-241.82%20KJ%2Fmol%29%5D)
![= -787 KJ/mol-[ -149.2 KJ/mol-967.28 KJ/mol]](https://tex.z-dn.net/?f=%3D%20-787%20KJ%2Fmol-%5B%20-149.2%20KJ%2Fmol-967.28%20KJ%2Fmol%5D)


<em>In this question, </em><em>the enthalpy of formation</em><em> has positive value and hence the </em><em>reaction is endothermic</em><em> in which the heat is released.
</em>