Optional Account giving `Could not resolve Accounts symbol Option` error

Question

I am new in solana smart-contract development and rust. Can anyone help me why i am getting this build time error Could not resolve Accounts symbol Option when using Optional Account in accounts struct. Any kind of help or info will be really helpful for me.

use anchor_lang::prelude::*;

declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");

#[program]
pub mod nft_project {
    use super::*;

    pub fn initialize(_ctx: Context<Initialize>) -> Result<()> {
        Ok(())
    }
}

#[derive(Accounts)]
pub struct Initialize <'info>{
    require_account: Account<'info,MyAccount>,
    optional_account: Option<Account<'info,Data>> 
}

#[account]
struct MyAccount{
    name: String,
}

#[account]
struct Data {
    name: String,
    age: u8
}

Answer 1

I was able to solve this problem after few hours. The problem was i was in a lower version of anchor but upgrading that didn't helped. Problem was coming from the CLI version of anchor , upgrading the anchor cli solved the issue. Not exactly but comment form Jon C helped me to reach there. Thank You.