Exam CIPP-A topic 1 question 10 discussion

SCENARIO – Please use the following to answer the next question:
Delilah is seeking employment in the marketing department of Good Mining Private Limited, an industry leader in drilling mines in Singapore. Delilah, while filling in the standard paper application form, is asked to provide details about emergency contacts, medical history, blood type and her insurance policy. These fields need to be filled in no matter which department Delilah applies to. The form also asks Delilah to expressly consent to the collection, use and disclosure of her personal data.
A week after submitting the form, Delilah is invited by Evan, the Director of Marketing at Good Mining, to coffee. Just before Delilah leaves, she gives her business card containing her current business contact information to Evan. Evan then uses the business card to add Delilah's details to Good Mining's business development database, which is kept on a local server. Good Mining uses the database to inform people about networking and client events that Good Mining organizes.
Why is it legal for Evan to add the information on Delilah's business card to the business development database?