To find an inequality to determine how many dozen donuts the junior class needs to sell to make at least $1,000, we can start by letting \( d \) represent the number of dozens sold.
The students are selling donuts for $12 per dozen, so the total revenue from selling \( d \) dozens can be expressed as \( 12d \).
To ensure they make at least $1,000, we set up the following inequality:
\[ 12d \geq 1000 \]
Now, we can solve the inequality for \( d \):
\[ d \geq \frac{1000}{12} \]
Calculating the right side:
\[ d \geq 83.33 \]
Since \( d \) represents the number of dozen donuts sold and can only be a whole number, we round up to the nearest whole number. Thus, the minimum number of dozens they need to sell is:
\[ d \geq 84 \]
So they need to sell at least 84 dozen donuts.
The final answer, based on the provided options, corresponds to:
$12d \geq 1000$ and 84.