Answer:
Muscular dystrophy (MD) is a group of inherited diseases in which the muscles that control movement (called voluntary muscles) progressively weaken. In some forms of this disease, the heart and other organs are also affected. There are nine major forms of muscular dystrophy: Myotonic.
In most cases, muscular dystrophy (MD) runs in families. It usually develops after inheriting a faulty gene from one or both parents. MD is caused by mutations (alterations) in the genes responsible for healthy muscle structure and function.
Explanation:
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True. Thought experiments are what he called them, it’s like meditation
Answer:
O a force that opposes motion
Explanation:
We have,
Surface area, 
The current varies wrt time t as :

(a) At t = 2 seconds, electrical charge is given by :

(b) Current is given by :

Instantaneous current at t = 1 s is,

(c) Current is, 
Current density is given by electric current per unit area.

Therefore, it is the required explanation.