Concept:
Every group of prime order is cyclic.
If
\[
O(G)=p
\]
where \(p\) is prime, then any non-identity element of \(G\) generates the entire group.
Step 1: Check the given orders.
The options are
\[
4,\quad 7,\quad 6,\quad 10
\]
Among these, only
\[
7
\]
is prime.
Step 2: Use the theorem.
If a group has prime order \(p\), then by Lagrange's theorem, the order of any non-identity element must divide \(p\).
The divisors of \(p\) are
\[
1\quad \text{and}\quad p
\]
A non-identity element cannot have order \(1\), so it must have order \(p\).
Thus it generates the whole group.
Step 3: Apply to \(O(G)=7\).
Since \(7\) is prime, any group of order \(7\) is cyclic.
Step 4: Final answer.
\[
\boxed{7}
\]