Step 1: Define the terms related to computer programs.
High-level language: A programming language that is closer to human language and thought (e.g., Python, Java, C++, Fortran). It needs to be translated into machine-readable code before a computer can execute it.
Source program (or source code): This is the version of a program written by a human programmer in a high-level programming language. It is human-readable and contains the instructions as written by the programmer.
Object program (or object code): This is the output of a compiler or assembler, which translates the source code into machine language (or an intermediate form) that a computer's processor can understand and execute. It is usually in binary format and not directly human-readable.
Basic program: This specifically refers to a program written in the BASIC (Beginner's All-purpose Symbolic Instruction Code) programming language. While BASIC is a high-level language, "Basic program" is a specific type of program, not a general term for any program written in a high-level language.
Application program (or application software): This is a computer program designed to perform a specific task for the user (e.g., word processor, web browser, game). An application program can be written in a high-level language, but the term refers to its function or purpose, not its raw, uncompiled form.
Step 2: Identify the correct term for a program written in a high-level language.
When a programmer writes code in a high-level language, the resulting human-readable set of instructions is universally referred to as the source program or source code. This source code is then compiled or interpreted to create an executable program.
The final answer is \( \boxed{\text{1}} \).