I keep seeing Cannot use instance member 'inputOptions' within property initializer; property initializers run before 'self' is available

Question

import SwiftUI

struct ContentView: View {
    let inputOptions = ["Celcius","Fahrenheit","Kelvin"]
    let outputOptions = ["Celcius","Fahrenheit","Kelvin"]
    @State private var selectedInput = "Celcius"
    @State private var inputValue : Int = 0
    @State private var selectedOutput = "Fahrenheit"
    let inputCelcius = inputOptions[0] // THIS IS WHERE ERROR POPS UP
    var body: some View {
        NavigationView{
            Form{
                Section{
                    Picker("Select input", selection: $selectedInput) {
                        ForEach(inputOptions, id: \.self) {
                            Text($0)
                        }
                    }
                    TextField("Amount", value: $inputValue, format: .number)
                } header : {
                    Text("Select conversion value and input value")
                }
                Section{
                    Picker("Select output", selection: $selectedOutput) {
                        ForEach(outputOptions, id: \.self) {
                            Text($0)
                        }
                    }
                
                } header : {
                Text("Select conversion value and output value")
                }
            }

            .navigationTitle("UnitConversion")
            .navigationBarTitleDisplayMode(.inline)
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

All i'm trying to do is create variables containing individual values of my inputOptions Array. Keep seeing "Cannot use instance member 'inputOptions' within property initializer; property initializers run before 'self' is available". I understand this issue most likely has a basic fix, but I can't seem to find it. I'm new to Swift, and programming in general.