Introduction:
Direct speech is a form of speech that is quoted or reported exactly as it was spoken. It is often used to convey someone's exact words, thoughts, or feelings. In direct speech, we use words that indicate the speaker's words, such as "said," "told," or "asked."

Explanation:
The correct answer is option 'D' - all of the above. Let's take a closer look at each of the given options and understand why they are often used in sentences in direct speech.

a) Said:
" said" is a commonly used word in direct speech. It is used to indicate that someone is speaking or has spoken. For example:
- "I am tired," she said.
- "I want to go home," he said.

b) Told:
"told" is another word that is frequently used in direct speech. It is used when one person gives information, instructions, or advice to another person. For example:
- "I told him to be careful," she said.
- "He told me that he loves me," he said.

c) Asked:
"asked" is also a word commonly used in direct speech. It is used when someone is making a request, seeking information, or posing a question. For example:
- "Can you help me?" she asked.
- "What time is it?" he asked.

Conclusion:
In direct speech, words like "said," "told," and "asked" are often used to indicate the speaker's words, thoughts, or feelings. These words help to accurately quote or report what someone has said, making the dialogue more realistic and engaging. Therefore, the correct answer is option 'D' - all of the above.