Which of the following is a preventive control?

You are having problems while retrieving results after performing port scanning during internal testing. You verify that there are no security devices between you and the target system. When both stealth and connect scanning do not work, you decide to perform a NULL scan with NMAP. The first few systems scanned shows all ports open.
Which one of the following statements is probably true?

The GET method should never be used when sensitive data such as credit card is being sent to a CGI program. This is because any GET command will appear in the URL, and will be logged by any servers. For example, let's say that you've entered your credit card information into a form that uses the GET method. The URL may appear like this:
https://www.xsecurity-bank.com/creditcard.asp?cardnumber=453453433532234
The GET method appends the credit card number to the URL. This means that anyone with access to a server log will be able to obtain this information. How would you protect from this type of attack?

Look at the following SQL query.
SELECT * FROM product WHERE PCategory='computers' or 1=1--'
What will it return? Select the best answer.

Cyber Criminals have long employed the tactic of masking their true identity. In IP spoofing, an attacker gains unauthorized access to a computer or a network by making it appear that a malicious message has come from a trusted machine, by "spoofing" the IP address of that machine.
How would you detect IP spoofing?