answer ALL 3 multiple choice questions thanks :)))

a) Which ONE of the following operations is NOT part of data cleansing? [1 point] Detecting and correcting inaccurate data, such as matching cities to correct postcodes. O Outlier removal. O Data anonymization for privacy protection, eg. by removing personal names. O Replacing of ' n/a ' column entries with NULL values. O Detecting and removal of incomplete data entries. O Harmonization of data, such as converting string-representations of numerical data (eg. 'one') to equivalent numbers (eg. 1). O Transformation of data from different sources to the same units of measure (eg. uniformly using days for the values of a duration). b) What is ONE main benefit of relational databases? [1 point] Efficient execution of iterative algorithms over large data sets. The flexibility to not need to define a schema before data can be stored in a database. Schema declaration via the graphical notation of the entity-relationship model. Declarative querying: to be able to specify what a query result should look like rather than having to program on how to compute it. O The possibility to efficiently store and analyse unstructured multimedia data such as images or videos. c) Which of the following statements are differences between semi-structured data model (such as JSON or XML) and the relational data model? [2 points] O In the relational data model, every attribute must have a name and type, while in XML or JSON, data values can be given without any meta-data or even name. O The relational data model is based on relations (sets) of homogeneous tuples, while XML or JSON can represent data with tree-like, nested structures. O The relational data model is semi-structured (it supports NULL values), while XML is a rigidly structured data model. O The relational data model needs to specify a schema first, while semi-structured data is self-describing and hence can be parsed without a priori knowing the data's structure. O Unstructured text data must be first transformed into a semi-structured data model before it can be analysed; the relational data model does not help in this case