The question asks to identify correct formatting rules according to the MLA Handbook, 9th edition.

MLA Formatting Rules Analysis

Let's evaluate each statement based on MLA Handbook, 9th edition guidelines:

• A. One inch margin: Correct. The MLA Handbook mandates a 1-inch margin on all sides (top, bottom, left, and right) of the research paper.
• B. Co-ordinating conjunctions in bold: Incorrect. MLA style does not require co-ordinating conjunctions in titles to be bolded. Titles typically follow title case capitalization rules without extra formatting like bolding for specific word types.
• C. Slash between two nouns: Correct. A slash (/) can be used between words, such as paired nouns indicating opposites or alternatives (e.g., "he/she", "pass/fail"), although using 'and' or 'or' is often preferred for clarity. Its use in specific contexts like paired opposites is permissible.
• D. ‘Hanging indent’ in Works Cited: Correct. The Works Cited page uses a hanging indent, where the first line of each entry is flush left, and subsequent lines are indented approximately ½ inch (0.5 inches or 12.7 mm). The LaTeX expression for ½ is $\frac{1}{2}$.
• E. Subordinating conjunctions not in bold: Generally correct, but less definitive than A, C, and D. Similar to co-ordinating conjunctions, subordinating conjunctions are not typically bolded in titles. However, the primary rules highlighted in A, C, and D are more universally emphasized in MLA formatting guides.

Conclusion on Correct Options

Based on the analysis, statements A, C, and D represent correct formatting rules according to the MLA Handbook, 9th edition.

• A is correct (1-inch margins).
• C is correct (slash usage for paired nouns).
• D is correct (½ inch hanging indent).

Therefore, the correct option is the one that includes A, C, and D.