Tom is writing a software program that calculates the sales tax for online orders placed from various jurisdictions. the application includes a user-defined field that allows the entry of the total sale amount. tom would like to ensure that the data entered in this field is a properly formatted dollar amount. what technique should he use?

a. limit check
b. fail open
c. fail secure
d. input validation

What is domain name system (dns)? allows dynamic ip address allocation so users do not have to have a preconfigured ip address to use the network converts ip addresses into domains, or identifying labels that use a variety of recognizable naming conventions the efficient coexistence of telephone, video, and data communication within a single network, offering convenience and flexibility not possible with separate infrastructures the integration of communication channels into a single service