Final answer:
The correct answer is D. 1variable, as it starts with a number, which goes against the general conventions for naming variables in programming. Variable names typically start with a letter or an underscore.
Step-by-step explanation:
The question is asking to identify which option is not a valid variable name in programming. There are certain rules that are generally followed across multiple programming languages when it comes to naming variables. Typically, variable names must start with a letter or an underscore and cannot begin with a number. They can include letters, numbers, and underscores thereafter. Given these conventions, let's evaluate the options:
- A. variableOne - Valid: Starts with a letter and follows conventional naming patterns.
- B. oneVariable - Valid: Also starts with a letter and follows conventional naming patterns.
- C. variable1 - Valid: Starts with a letter and is subsequently followed by a number, which is permitted.
- D. 1variable - Not valid: Starts with a number, which is against the variable naming rules in most programming languages.
Therefore, the correct answer is D. 1variable, since it does not comply with the standard variable naming conventions.