Made the ValueType property for Option as to expose the ValueType property for Argument.

Author: MiYanni

src/System.CommandLine/Option.cs

@@ -62,6 +62,11 @@ public ArgumentArity Arity
         /// </summary>
         public bool Recursive { get; set; }
 
+        /// <summary>
+        /// Gets the <see cref="Type" /> that the option's parsed tokens will be converted to.
+        /// </summary>
+        public abstract Type ValueType { get; }
+
         /// <summary>
         /// Validators that will be called when the option is matched by the parser.
         /// </summary>

src/System.CommandLine/Option{T}.cs

@@ -44,6 +44,9 @@ public Func<ArgumentResult, T>? DefaultValueFactory
 
         internal sealed override Argument Argument => _argument;
 
+        /// <inheritdoc />
+        public override Type ValueType => _argument.ValueType;
+
         /// <summary>
         /// Configures the option to accept only the specified values, and to suggest them as command line completions.
         /// </summary>