We are given that the intercepts of the line are 3 and 4. The equation of the line in the intercept form is:
\[
\frac{x}{3} + \frac{y}{4} = 1
\]
The distance \( D \) of a line \( Ax + By + C = 0 \) from the origin is given by the formula:
\[
D = \frac{|C|}{\sqrt{A^2 + B^2}}
\]
In this case, we rewrite the line in the general form \( Ax + By + C = 0 \) as:
\[
\frac{x}{3} + \frac{y}{4} - 1 = 0 \quad \Rightarrow \quad 4x + 3y - 12 = 0
\]
Thus, \( A = 4, B = 3, C = -12 \).
Using the formula for distance:
\[
D = \frac{|(-12)|}{\sqrt{4^2 + 3^2}} = \frac{12}{\sqrt{16 + 9}} = \frac{12}{\sqrt{25}} = \frac{12}{5}
\]
Thus, the correct answer is \( \frac{12}{5} \) units.