How to find the set $A \subseteq \mathbb{N} $ that $A$ is the basic set for a given divisibility relation and a given HASSE-Diagram?

Question

How to find the set $A \subseteq \mathbb{N} $ that $A$ is the basic set for the divisibility relation:

$R_A=_{def} \{(m,n) | m,n \in A \wedge m ~ \text{divides} ~ n \} \subseteq A \times A$

for the following HASSE-Diagram

Answer 1

I must've been tired the first time. Here's a new and simpler picture:

Note that $6 = 2\cdot 3$, $15 = 3\cdot 5$, $25=5^2$, $30 = 2\cdot 3\cdot 5$, $75 = 3\cdot 5^2$, $125 = 5^3$, and $750 = 2\cdot 3\cdot 5^3$.