Answer:
D) True. the protostar rotates more quickly.
Explanation:
If the system is isolated, the angular momentum must be retained.
Initial
    L₀ = I w₀
Final
    [tex]L_{f}[/tex] = [tex]I_{f}[/tex]  [tex]w_{f}[/tex]
   L₀ = [tex]L_{f}[/tex]
   I w₀ = [tex]I_{f}[/tex][tex]w_{f}[/tex]
   [tex]w_{f}[/tex]  = I /[tex]I_{f}[/tex] w₀
In general, the radius of the cloud decreases significantly to form the star, the moment of inertia must decrease, so the angular velocity must increase
Let's examine the answers
A) False. The opposite happens
B) False. Speed ​​changes
C) False. For this there must be an external force, which does not exist
D) True. You agree with the above