$7.$ The investments of Harlon Enterprises included the following cost and fair value amounts $($$ in millions$)$:

Fair Value, December $31$

Equity Investments Cost $20242025$

A Corporation Shares $$20$ $$14$ N$/$A

B Corporation Shares $3538$ $$37$

C Corporation Shares $15$ N$/$A $14$

D Industries Shares $454650$

Totals $$115$ $$95$ $$101$

Additional information:

$$ Harlon accounts for its equity investment portfolio using the fair value method.

$$ Harlon sold its holdings of A Corporation shares on June $1,2025$ for $$17$ million.

$$ On September $12,2025,$ Harlon purchased the C Corporation shares for $$15$ million.

a$.$ What is the effect of the sale of the A Corporation shares and the purchase and holding of the C Corporation shares on Harlon$$s $2025$ net income $($ignore tax effects$)?$

b$.$ What is the effect of holding B Corporation shares and D Corporation shares on Harlon$$s $2025$ net income $($ignore tax effects$)?$

c$.$ At what amount should Harlon report its equity investment portfolio in its $2025$ balance sheet?