Option A.
Step-by-step explanation:
We need to find the algebraic expression for the word phrase.
The given word phrase is "30% of m".
The algebraic expression for the given phrase is
![\dfrac{30}{100}\times m](/tpl/images/0552/5129/96f71.png)
Cancel out common facors.
![\dfrac{3}{10}\times m](/tpl/images/0552/5129/06cc4.png)
![0.3\times m](/tpl/images/0552/5129/3810a.png)
After multiplication, we get
![0.3m](/tpl/images/0552/5129/3389c.png)
The required expression is 0.30 m.
Therefore, the correct option is A.