Sample code:

<apex:page controller="sample">
    
    <apex:form >
    
    <apex:pageBlock >
        <apex:commandButton value="Get" action="{!get}"/>
    </apex:pageBlock>
    
    <apex:pageBlock id = "a" >
        <apex:selectList value="{!answer}" size="1">
            <apex:selectOptions value="{!answers}"/>
        </apex:selectList>        
    </apex:pageBlock>    

    </apex:form>

</apex:page>

public class sample
{
    public List<Account> act = new List<Account>();
    public List<String> values = new List<String>();
    public String answer;

    public void get()
    {
        String sql = 'SELECT Name FROM Account LIMIT 10';
        act = Database.Query(sql);
        
        for(Account a:act)
        {
            values.add(a.Name);
        }
    }

    public List<SelectOption> getanswers()
    {
        List<SelectOption> options = new List<SelectOption>();
        for(String s:values)
        {
            options.add(new SelectOption(s,s));
        }        
        return options;
    }
        
    public String getanswer()
    {
        return answer;
    }
 
    public void setanswer(String answer)
    {
        this.answer = answer;
    }      
}

If this is the solution, kindly mark this as solution.

Cheers !!!