Which of the following is considered a secure coding practice?*Using regular expressions to validate all inputsImplementing least privilege access controlStoring passwords in plain text with a unique user identifierRelying on client-side validation for security checks

The secure coding practices among the options provided are:

1. Using regular expressions to validate all inputs: This is a secure coding practice as it helps to ensure that only valid data is accepted by the system. Regular expressions can be used to check if the input data matches a specific pattern, which can help to prevent attacks such as SQL injection.

2. Implementing least privilege access control: This is also a secure coding practice. The principle of least privilege states that a user should be given the minimum levels of access – or permissions – they need to perform their work functions. This can help to minimize the potential damage caused if an attacker is able to compromise a user account.

The other two options are not considered secure coding practices:

1. Storing passwords in plain text with a unique user identifier: This is not a secure practice as if an attacker is able to gain access to the system, they would be able to easily read and use the passwords.

2. Relying on client-side validation for security checks: This is also not a secure practice as client-side validation can be easily bypassed by an attacker. It is important to also have server-side validation to ensure security.