objectivity and independence

Definition - Independence is: (a) Independence of mind – the state of mind that permits the expression of a conclusion without being affected by influences that compromise professional judgement, thereby allowing an individual to act with INTEGRITY, and exercise OBJECTIVITY and professional skepticism. (b) Independence in appearance – the avoidance of facts and circumstances that are so significant that a reasonable and informed third party would be likely to conclude, weighing all the specific facts and circumstances, that a firm’s, or a member of the audit or assurance team’s, INTEGRITY, OBJECTIVITY or professional skepticism has been compromised. Independence is not a fundamental principle but underpins two fundamental principles - integrity and objectivity. Ethical threats are not confined to those that affect objectivity and/or integrity but ANY of the fundamental principles - so also include threats to professional competence and due care, confidentiality and professional behaviour. So, for example, a high audit fee creates a self-interest threat to independence (both integrity and objectivity) but pressure to accept a low audit fee (an intimidation threat) might result in an inappropriate reduction in the extent of audit work performed. Although there is an integrity aspect to this there is also a threat to professional competence.

so when it should have been independence and if i write objectivity, i won't get full credit ?

You would get full credit - objectivity is the fundamental principle (and you don't have to state every fundamental principle that may be affected by a threat in order to earn the mark).