What are two considerations for deciding to use a roll-up summary field?
Choose 2 answers

Roll-up summary field can be performed on formula fields, but if their formula contains an #error result, it may affect the summary value.
Roll-up cannot be performed on formula field
Roll-up summary field do not cause validation rules on the parent object unless that object is edited separately.
Roll-up cannot be performed on formula fields that use cross-object references or on-the-fly calculations such as NOW()

Please tell me correct ans.
 

What are two considerations for deciding to use a roll-up summary field?
Choose 2 answers

Roll-up summary field can be performed on formula fields, but if their formula contains an #error result, it may affect the summary value.
Roll-up cannot be performed on formula field
Roll-up summary field do not cause validation rules on the parent object unless that object is edited separately.
Roll-up cannot be performed on formula fields that use cross-object references or on-the-fly calculations such as NOW()

Please tell me correct ans.
 

A developer created a Lightning Component to display a short text summary for an object and wants to use it with multiple Apex classes.
How should the developer design the Apex classes?

Extend each class from the same base class that has a method getTextSummary() that returns the summary.
Have each class define method getTextSummary() that returns the summary.
Have each class define method getObject() that returns the sObject that is controlled by the Apex class.
Have each class implement an interface that defines method getTextSummary() that returns the summary.

Please let me know which is correct answer form above.